U.S. patent application number 13/327341 was filed with the patent office on 2013-06-20 for braking system and method for a towed vehicle.
This patent application is currently assigned to ROBERT BOSCH GMBH. The applicant listed for this patent is Diego Cusi. Invention is credited to Diego Cusi.
Application Number | 20130158826 13/327341 |
Document ID | / |
Family ID | 47470219 |
Filed Date | 2013-06-20 |
United States Patent
Application |
20130158826 |
Kind Code |
A1 |
Cusi; Diego |
June 20, 2013 |
BRAKING SYSTEM AND METHOD FOR A TOWED VEHICLE
Abstract
A braking assistance system for a vehicle towed by a towing
vehicle. The braking assistance system includes at least one sensor
configured to be coupled to the towed vehicle and to detect
information about at the towed vehicle and the towing vehicle, and
an electronic control unit having a processor. The electronic
control unit is in electronic communication with the sensor to
receive information about the towed vehicle and the towing vehicle.
The processor is configured to determine an electrical connection
between the towing vehicle and the towed vehicle, determine a
deceleration of the towed vehicle and the towing vehicle based on
the information from the at least one sensor, identify a brake
assist situation, and initiate a brake control operation to control
braking of the towed vehicle during the brake assist situation.
Inventors: |
Cusi; Diego; (Farmington
Hills, MI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Cusi; Diego |
Farmington Hills |
MI |
US |
|
|
Assignee: |
ROBERT BOSCH GMBH
Stuttgart
DE
|
Family ID: |
47470219 |
Appl. No.: |
13/327341 |
Filed: |
December 15, 2011 |
Current U.S.
Class: |
701/70 |
Current CPC
Class: |
B60T 8/1708 20130101;
B60T 2201/03 20130101; B60T 2230/06 20130101 |
Class at
Publication: |
701/70 |
International
Class: |
B60T 7/20 20060101
B60T007/20; B60T 8/17 20060101 B60T008/17; G06F 19/00 20110101
G06F019/00 |
Claims
1. A braking assistance system for a vehicle towed by a towing
vehicle, the braking assistance system comprising: at least one
sensor configured to be coupled to the towed vehicle and to detect
information about at the towed vehicle and the towing vehicle; and
an electronic control unit having a processor, the electronic
control unit in electronic communication with the sensor to receive
information about the towed vehicle and the towing vehicle, the
processor configured to determine an electrical connection between
the towing vehicle and the towed vehicle, determine a deceleration
of the towed vehicle and the towing vehicle based on the
information from the at least one sensor, identify a brake assist
situation, and initiate a brake control operation to control
braking of the towed vehicle during the brake assist situation.
2. The system of claim 1, wherein the towed vehicle is mechanically
connected to the towing vehicle.
3. The system of claim 1, where in the processor is further
configured to monitor a brake signal from a braking system of the
towing vehicle, and wherein the brake assist situation is
determined at least in part by using the brake signal.
4. The system of claim 3, wherein the braking signal indicates that
a driver has applied brakes of the towing vehicle.
5. The system of claim 1, wherein the sensor is a longitudinal
acceleration sensor.
6. The system of claim 1, wherein the wherein the electronic
control unit is configured to communicate with a braking control
system of the towed vehicle.
7. The system of claim 6, wherein the electronic control unit is
configured to communicate with a stability control system, and
wherein the stability control system is configured to initiate the
brake control operation to control the vehicle during the brake
assist situation.
8. The system of claim 1, wherein the processor is further
configured to determine a brake assist situation and to initiate a
brake control operation when the processor fails to determine an
electrical connection between the towing vehicle and the towed
vehicle.
9. The system of claim 1, wherein the processor is further
configured to determine a brake assist situation when the
deceleration of the towed vehicle and the towing vehicle exceeds a
threshold.
10. A method for braking assistance of a vehicle towed by a towing
vehicle, the method comprising: detecting, by at least one sensor
coupled to the towed vehicle, information about at the towed
vehicle and the towing vehicle; connecting an electronic control
unit having a processor with the sensor; receiving, at the
electronic control unit, information from the sensor about the
towed vehicle and the towing vehicle; operating the processor of
the electronic control unit to determine an electrical connection
between the towing vehicle and the towed vehicle, determine a
deceleration of the towed vehicle and the towing vehicle based on
the information from the at least one sensor, identify a brake
assist situation, and initiate a brake control operation to control
braking of the towed vehicle during the brake assist situation.
11. The method of claim 10, further comprising monitoring, by the
processor, a brake signal from a braking system of the towing
vehicle, and wherein the brake assist situation is determined at
least in part by using the brake signal.
12. The method of claim 11, wherein the braking signal indicates
that a driver has applied brakes of the towing vehicle.
13. The method of claim 10, wherein the sensor is a longitudinal
acceleration sensor.
14. The method of claim 10, further comprising communicating, by
the processor, with a braking control system of the towed
vehicle.
15. The method of claim 10, further comprising communicating, by
the processor, with a stability control system.
16. The method of claim 10, further comprising initiating, by the
stability control system, the brake control operation to control
the vehicle during the brake assist situation.
17. The method of claim 10, further comprising initiating a brake
control operation when the processor fails to determine an
electrical connection between the towing vehicle and the towed
vehicle.
18. The method of claim 10, wherein the brake assist situation is
identified when the deceleration of the towed vehicle and the
towing vehicle exceeds a threshold.
Description
BACKGROUND
[0001] The present invention relates to vehicle towing systems.
More specifically, the invention relates to braking systems for
towed vehicles.
SUMMARY
[0002] Very often, vehicles are towed or moved by towing vehicles
(e.g., a recreation vehicle or RV towing a small passenger vehicle
or automobile). The vehicle being towed can sway back and forth for
many different reasons and this sway can create stability problems
for the towing vehicle. In many situations, the towed vehicle is
braked solely by using the braking system of the towing vehicle. In
other words, the brakes of the towing vehicle slow or stop the
towing vehicle. The towed vehicle, as a consequence of being
mechanically linked to the towing vehicle, is slowed or stopped.
However, in many countries there is a legal requirement that the
towed vehicle include independents means for braking Standard
devices used for slowing down the towed vehicle include the "brake
buddy" or other similar mechanical systems. Although these
technologies provide means for stopping the towed vehicle, they
require additional installation and, in some situations, are still
not sufficient to assist during braking and stopping of the towed
vehicles.
[0003] In one embodiment, the invention provides a braking
assistance system for a vehicle towed by a towing vehicle. The
braking assistance system includes at least one sensor configured
to be coupled to the towed vehicle and to detect information about
the towed vehicle and the towing vehicle, and an electronic control
unit having a processor. The electronic control unit is in
electronic communication with the sensor to receive information
about the towed vehicle and the towing vehicle. The processor is
configured (such as by executing certain instructions stored on a
computer readable medium) to determine an electrical connection
between the towing vehicle and the towed vehicle, determine a
deceleration of the towed vehicle and the towing vehicle based on
the information from the at least one sensor, identify a brake
assist situation, and initiate a brake control operation to control
braking of the towed vehicle during the brake assist situation.
[0004] In another embodiment, the invention provides a method, at
least a part of which may be implemented with a computer, of
providing braking assistance of a vehicle towed by a towing
vehicle. The method includes detecting, by at least one sensor
coupled to the towed vehicle, information about the towed vehicle
and the towing vehicle, and connecting an electronic control unit
having a processor with the sensor. The processor receives, at the
electronic control unit, information from the sensor about the
towed vehicle and the towing vehicle. The method further includes
operating the processor of the electronic control unit to determine
an electrical connection between the towing vehicle and the towed
vehicle, determine a deceleration of the towed vehicle and the
towing vehicle based on the information from the at least one
sensor, identify a brake assist situation, and initiate a brake
control operation to control braking of the towed vehicle during
the brake assist situation.
[0005] Other aspects of the invention will become apparent by
consideration of the detailed description and accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a side, elevation view of a towing vehicle and a
towed vehicle including a braking assistance system.
[0007] FIG. 2 is a schematic illustration of the braking assistance
system of FIG. 1.
[0008] FIG. 3 is a flow chart illustrating a process for brake
assistance of a towed vehicle performed by the braking assistance
system of FIG. 1.
[0009] FIG. 4 illustrates a braking control subsystem of the
braking assistance system of FIG. 1.
DETAILED DESCRIPTION
[0010] Before any embodiments of the invention are explained in
detail, it is to be understood that the invention is not limited in
its application to the details of construction and the arrangement
of components set forth in the following description or illustrated
in the following drawings. The invention is capable of other
embodiments and of being practiced or of being carried out in
various ways.
[0011] In addition, it should be understood that embodiments of the
invention may include hardware, software, and electronic components
or modules that, for purposes of discussion, may be illustrated and
described as if the majority of the components were implemented
solely in hardware. However, one of ordinary skill in the art,
based on a reading of this detailed description, would recognize
that, in at least one embodiment, the electronic based aspects of
the invention may be implemented in software (e.g., stored on
non-transitory computer-readable medium). As such, it should be
noted that a plurality of hardware and software based devices, as
well as a plurality of different structural components may be
utilized to implement the invention.
[0012] FIG. 1 illustrates a towing vehicle 3 (e.g., a RV) and a
towed vehicle 5 (e.g., a car) having a plurality of wheels 8. In
other embodiments, the braking system discussed below can be
applied to different types of vehicles. The towing vehicle 3 is
coupled to the towed vehicle 5 by a mechanical connection (e.g., a
hitch system 6). In one embodiment, the hitch system 6 includes a
hitch ball and a ball receiver. Other hitching systems may be used
to couple the towing vehicle 3 to the towed vehicle 5. An operator
(i.e., a driver) of the towing vehicle 3 operates a throttle and
brake, and turns a steering wheel to direct the towing vehicle in a
desired direction or to slow down the towing vehicle. In addition,
the towing vehicle 3 is connected to the towed vehicle 5 by an
electrical connection. In some embodiments, the electrical
connection is between the brake light switches of both vehicles.
Therefore, when the operator applies the brakes of the towing
vehicles 3, the brake lights of the towed vehicle 5 provide a
signal indicative of that action.
[0013] The towed vehicle 5 includes, among other systems, a vehicle
stability control system 7, such as Electronic Stability Program
system ("ESP.RTM.") created by Bosch, and a braking assistance
system 11 used to assist the towed vehicle 5 during braking In one
embodiment of the invention, the braking assistance system 11 is
incorporated within the stability control 7. For example and as
further explained below, the braking assistance system 11 is
implemented in the form of software embedded within the existing
stability control system 7. In another embodiment, the braking
assistance system 11 is not part of the stability control system 7
and operates independently from the stability control system 7.
[0014] The braking assistance system 11 includes one or mores
sensors 14, an electronic control unit ("ECU") 18, and a plurality
of control subsystems 19-21. The subsystems can include a braking
control subsystem 19, a steering control subsystem 20, and a
drivetrain control subsystem 21. Additional subsystems include a
traction control subsystem, a stability subsystem, and the like
(not shown). In one embodiment, an stability control controller of
the stability control system 7 is modified with software in
accordance with the teachings herein and used as the ECU 18. The
braking assistance system 11 monitors the acceleration of the
towing vehicle 3 and the towed vehicle 5. The system 11 determines
a brake assist situation (e.g., when the towing vehicle 3 is
braking and the vehicles 3 and 5 are decelerating), and initiates a
brake control operation to control braking of the towed vehicle 5
during the brake assist situation.
[0015] The sensors 14 are used to sense current operating
conditions of the towed vehicle 5 and the towing vehicle 3 and
provide information representative of the same to the ECU 18. The
sensors 14 transmit sensor measurement data (e.g., as analog data
or digital data). The sensors 14 include, for example, a
longitudinal acceleration senor, a speed sensor, a deceleration
sensor, a wheel speed sensor, a yaw rate sensor, a steering angle
sensor, a brake pressure sensor, or other types of sensing
technology configured to monitor the vehicle 5. The sensors 14 can
be positioned at different locations of the towed vehicle 5. In
embodiments utilizing the stability control system 7, the sensors
14 are the sensors incorporated in that system. If the sensors are
equipped with calibration circuitry or a processor, the sensors can
internally convert the sensed conditions to a calibrated form.
Otherwise, the sensed conditions can be converted into calibrated
signals by other external processes (e.g., the ECU 18).
[0016] The sensors 14, the stability control system 7, and the ECU
18 are connected to a bus or network, such as a controller area
network ("CAN") bus 22. The CAN bus 22 is connected to other
vehicle systems (e.g., subsystems 19-21). Although the components
are shown connected via a bus or network, other connections (such
as direct wired or wireless connections) can be used to connect the
sensors 14 to the ECU 18. The ECU 18 includes a data processing
module 25 configured to process the information obtained from the
sensors 14 while the towed vehicle 5 travels behind the towing
vehicle 3.
[0017] FIG. 2 schematically illustrates the braking assistance
system 11 in more detail. As shown in FIG. 2, the system 11
includes the ECU 18, the sensors 14, the stability control system
7, and the bus 22. As further discussed below, the ECU 18 can also
communicate with other devices or systems through the bus 22.
However, the ECU 18 can also obtain information (i.e., data)
directly from the sensors 14 rather than over the bus 22. As
illustrated in FIG. 2, the ECU 18 of the system 11 is also
connected to the braking subsystem 19, the steering subsystem 20,
and the drivetrain subsystem 21.
[0018] As shown in FIG. 2, the ECU 18 includes an input/output
interface 60, an electronic processing unit ("EPU") or a processor
62, and one or more non-transitory memory modules, such as a random
access memory ("RAM") 64 and read-only memory ("ROM") 65. The
input/output interface 60 transmits and receives data over the bus
22, including data from the sensors 14. It should be understood
that the ECU 18 can include multiple processors, additional
computer-readable medium modules, multiple I/O interfaces, and/or
other additional components or modules (e.g., hardware, software,
or a combination thereof).
[0019] The input/output interface 60 allows the ECU 18 to
communicate with other components inside the towed vehicle 5 (e.g.,
over the CAN 22) and outside of the towed vehicle 5. In other
words, the input/output interface 60 receives data from outside the
ECU 18 and outputs information outside the ECU 18. For example, the
input/output interface 60 can include a network interface, such as
a vehicle-to-vehicle communication device or a wireless network
card that allows the system 11 to send and receive information over
a network, such as a local area network or the Internet. In some
embodiments, the input/output interface 60 is located external to
the ECU 18 and may receive data from other devices or systems
located in the towed vehicle 5. Similarly, the ECU 18 may be
included within another vehicle control system rather than
configured as a separate component (e.g., within the stability
control system 7). In addition, although not shown in FIG. 2,
conditioning circuits or peripheral drivers may be used to
interface the ECU 18 with the sensors 14.
[0020] In one embodiment, the ECU 18 is configured to communicate
with the stability control system 7, the braking subsystem 19, the
steering subsystem 20, and the drivetrain subsystem 21. The ECU 18
is configured to receive information from these systems. For
example, the ECU 18 receives information about the state of the
towed vehicle 5 (e.g., speed, velocity, acceleration/deceleration,
yaw rate, and steering angle, etc.) from the stability control
system 7 or the subsystems 19-21.
[0021] The EPU 62 receives the information from the input/output
interface 60 and processes the information by executing one or more
instructions or modules (e.g., the data processing module 25,
acceleration module 26, brake assist situation identification
module 27, etc.). The instructions or modules are stored in
non-transitory computer-readable medium, such as ROM 65. The EPU 62
stores and retrieves information (e.g., information received from
the bus 22 or information generated by instructions or modules
executed by the EPU 62) to and from the RAM 64. The non-transitory
computer readable medium 65 includes volatile memory, non-volatile
memory, or a combination thereof. The computer-readable medium 65
stores operating system software, applications and/or instructions,
data, or combinations thereof. It should be understood that
although only a single EPU, RAM, ROM, and input/output interface
are illustrated in FIG. 2, the ECU 18 can include multiple
processing units, memory modules, and/or input/output
interfaces.
[0022] The processing EPU 62 executes software instructions that
are capable of being stored in the RAM (e.g., during execution),
the ROM 65 (e.g., on a generally permanent basis), or another
non-transitory computer readable medium such as another memory or a
disc. The software includes, for example, firmware, one or more
applications, program data, filters, rules, one or more program
modules, and other executable instructions. The controller ECU 18
is configured to retrieve from memory and execute, among other
things, instructions related to the control processes and methods
described herein. In other constructions, the ECU 18 includes
additional, fewer, or different components.
[0023] Although the ECU 18 is illustrated in FIGS. 1-2 as a
separate component from the sensors 14, in some embodiments the ECU
18 is included in the sensors 14. In other embodiments, the ECU 18
is separate from the sensors 14 to prevent faults (e.g.,
electrical, mechanical, or software-based) in the sensors 14 from
affecting the functionality provided by the ECU 18. The ECU 18 can
also be combined with other vehicle controllers.
[0024] The instructions stored in the computer-readable medium
provide particular functionality when executed by the EPU 62. The
ECU 18 includes hardware and software and these components
cooperate to execute the logic of the braking assistance system 11.
As shown in FIG. 2, the input/output interface 60 of the ECU 18
receives data from the sensors 14 and provides the data to the
processor 62 of the ECU 18. In some embodiments, the input/output
interface 60 processes the data from the sensor 14 before providing
the data to the processor 62 of the ECU 18. As described in more
detail below with respect to FIGS. 3 and 4, the processor 62
processes the received data and determines a brake assist
situation. The processor 62 initiates a brake control operation to
control braking of the towed vehicle 5. During the brake control
operation, the processor 62 generates control signals to at least
one of the subsystems 19-21 to, for example, slow the towed vehicle
5 by using its own braking system 19.
[0025] A brake assist situation is identified as a situation where
the system 11 has detected, by using the information form the
sensors 14, that the brakes on the towing vehicle 3 have been
applied. In that situation, the towing vehicle 3 and, consequently,
the towed vehicle 5 begin to decelerate. The goal of the braking
assistance system 11 is to control the braking of the towed vehicle
5 to assist with slowing down during the detected brake assist
situation. When the braking assistance system 11 is integrated
within the stability control system 7 or configured to communicate
with that system, the stability control system 7 controls the
braking assistance system 11. Thus, the stability control system 7
begins brake control operation without the driver's input when the
towing vehicle 3 is braking, the vehicles 3 and 5 are decelerating
at a predetermined level set by the stability control system 7, and
the braking assistance system 11 detects a brake assist
situation.
[0026] FIG. 3 illustrates a method 100 of brake assistance for the
towed vehicle 5 performed by the ECU 18 according to one embodiment
of the invention. For simplicity, one iteration of the logic of
FIG. 3 is explained in detail below. In this embodiment, the
braking assistance system 11 is operating together with the
stability control system 7. However, in other embodiments, the
assistance system 11 can operate independently from the stability
control system 7. Various steps described herein with respect to
the process 100 are capable of being executed simultaneously, in
parallel, or in another order that differs from the illustrated
serial manner of execution. The process 100 is also capable of
being executed using additional or fewer steps than are shown in
the illustrated embodiment.
[0027] As shown in FIG. 3, the process begins with determining
whether the towed vehicle 5 is electrically connected to the towing
vehicle 5 (at step 105). For example, this is done by detecting a
connection between the brake light switches of both vehicles. If
there is no electrical connection between the vehicles, the process
100 returns to its starting point. If, on the other hand, the ECU
confirms the existence of an electrical connection signal between
the towing vehicle 3 and the towed vehicle 5, the process proceeds
to step 105. In other embodiments, the system 11 is configured to
determine a brake assist situation and to initiate a brake control
operation when the system 11 determines that there is no electrical
connection between the vehicles. This feature is designed to
prevent situations where the towed vehicle 5 is unintentionally
disengaged from the towing vehicle 3 while the vehicles are
travelling. That way, the towed vehicle 5 will stop by using its
own braking system.
[0028] In the next step, the sensors 14 detect information about
the current operating conditions of the vehicle 5 (at step 107).
Because the towed vehicle 5 is mechanically connected to the towing
vehicle 3, the sensors 14 of the vehicle 5 can detect the combined
acceleration of both vehicles. The sensors 14 transfer the acquired
data to the ECU 18 (at step 110). The data processing module 25
processes the received data and the acceleration module 26
determines the current acceleration or deceleration level of the
vehicles 3 and 5 (at step 115). Next, the ECU 18 compares the
detected acceleration with a threshold acceleration value (at step
120). The threshold acceleration value can be a predetermined value
retrieved from memory or can be dynamically determined by the
processor 62 based on the information received from the sensors 14.
When the processor determines that the towing vehicle is braking
(e.g., by a signal received from the brake light switches) at step
123, and the acceleration of the vehicle 5 (e.g., a negative
acceleration or a deceleration) exceeds the threshold acceleration
value, the brake assist situation identification module 27
determines that a brake assist situation exists (at step 125).
[0029] Next, the processor 62 initiates a brake control operation
to control the braking of the towed vehicle 5 during the brake
assist situation (at step 130). During the brake control operation,
the processor 62 generates command input signals to the braking
subsystem 19. The braking subsystem 19 (explained in more detail
below) applies brake pressure to the wheels 8 of the vehicle 5 and
slows the towed vehicle 5.
[0030] FIG. 4 illustrates the braking control subsystem 19. The
braking control subsystem 19 includes an electronic brake
controller 200, a plurality of electronically controlled brakes
205, a brake sensor 210, and a braking control converter 220. The
brake controller 200 receives a control signal from the ECU 18 to
begin a brake control operation. The braking control device 220
receives the command input signals and converts them to braking
control signals that are sent to the electronic brake controller
200. The electronic brake controller 200 then generates and sends
corresponding brake signals to each of the brakes 205, which
actuate valves within the brakes 205 with variable forces. The
brake sensor 210 monitors the braking forces that are applied to
the wheels 8 by each of the brakes 205. The brake sensor 210 is
connected to the ECU 18 such that the braking control device 220
receives the information related to the actual braking forces
applied to the wheels 8. The braking control device 220 uses the
braking information to modify or maintain the brake control signals
that are applied to each brake 205. For example, the front right
and rear right brakes can apply a greater braking force than the
braking force that is applied (if any) to the left front and left
rear brakes. In other embodiments of the invention, different
braking control subsystem configurations and components can be
used.
* * * * *